Another plotline could be the challenges they face during the pregnancy. Since Loki has his mischievous nature and Sif is a strong - willed warrior, they might have different approaches to the pregnancy. There could be conflicts and then reconciliations as they figure out how to deal with the situation together. This can involve things like dealing with Asgardian traditions regarding pregnancy and childbirth.
A plotline might involve Loki and Sif coming to terms with their relationship while dealing with the pregnancy. For example, they could have had a rocky relationship before and the pregnancy forces them to re - evaluate their feelings for each other. There could also be a plot where they have to protect the unborn child from some sort of threat, either from within Asgard or from other realms.
I'm not sure about specific Loki and Sif pregnant fanfiction off the top of my head. But you can try searching on fanfiction websites like Archive of Our Own. They usually have a wide range of fanfictions and you can use the search filters to look for ones related to Loki, Sif and the pregnancy concept.
One common theme is redemption. Loki often has to redeem himself in the eyes of Sif for their love to develop. For example, in many fanfics, he might start off as a trickster causing trouble for Sif, but then he changes for the better.
Love and loyalty are also prevalent themes. Fanfictions show how their love for each other grows and endures despite the odds. They might face external threats or internal conflicts, but their loyalty to one another remains strong. This theme helps to create a more emotional and romantic aspect to the stories about their married life.
One great Loki and Sif fanfiction is 'A Different Path'. It explores an alternate universe where Loki and Sif have to team up for a quest. The story is well - written, with great character development. It shows a side of Loki that is more vulnerable and a strong - willed Sif.
One common theme is the reaction of the Asgardian community. Since Thor and Sif are important figures, their pregnancy could have a big impact on the society. Another theme might be how they handle the challenges of impending parenthood while also dealing with their duties as warriors and protectors.
One popular theme is redemption. Loki is often a character in need of redemption, and Sif can be the one who either helps him on that path or is a witness to his journey. For example, in many fics, Loki tries to make up for his past wrongs against Sif and Asgard.
One common theme is self - discovery. Loki, who is often portrayed as a complex and somewhat self - centered character, discovers new aspects of himself during pregnancy. For example, he may find a new sense of responsibility.
A theme that often comes up is the struggle for acceptance. In the world of Asgard or other settings, a male getting pregnant is not a common occurrence. So Loki has to face the prejudices and lack of understanding from others. Also, there is the theme of self - discovery. Through this unique experience, Loki learns more about his own capabilities and limitations.
You can try looking on fanfiction websites such as Archive of Our Own (AO3). There are often a variety of fanfictions on different themes including ones about Loki and Sif. Just use the search function and type in 'Loki and Sif pregnant' to see what comes up.